Search Results (349)

Dilute-solution properties are important sources of information on the structure of macromolecules. Analyzing experimental data and extracting information on structural properties require theoretical and computational resources. The resources needed to study rigid particles are manageable; however, studying flexible particles is more challenging. This is because, unlike rigid bodies, and as a consequence of the conformational variability arising from flexibility, flexible particles do not have a definite size and shape. In addition to their overall translational and rotational Brownian motion, the dynamics of flexible particles in solution has an internal component: size/shape conformational fluctuations. In order to facilitate the study of flexible macromolecule hydrodynamics, we have implemented existing theories within several computer programs. MONTEHYDRO combines Monte Carlo simulations based on the importance-sampling algorithm to generate conformations from which, in addition to conformational quantities, the hydrodynamic properties of flexible particles can be obtained using rigid-body treatment. SIMUFLEX is a suite based on a Brownian dynamics simulation of macromolecules, comprising BROWFLEX, for the generation of trajectories, and ANAFLEX, for the calculation of static and time-dependent properties as well as the simulation of single-particle events. In this paper, we present some concepts which are fundamental to the methods implemented in those computational tools, as well as examples of their utilization in various biomacromolecule applications, with a particular emphasis on double-stranded DNA in various cases: coarse-grained double-helical models for moderately short DNA; the worm-like model treatment of DNA over an extremely wide range of sizes (from 8 to 200,000 base pairs); and the problem of the anomalous rotational-speed dependence of the sedimentation coefficient of very long DNA. SIMUFLEX has also been particularly useful for studying intrinsically partially disordered proteins, whose structure comprises both ordered, globular domains as well as flexible tail and linker chains. To illustrate applications in the field of synthetic polymers, we describe a study on dendrimers, with aspects related to drug delivery in targeted therapies. Full article

Sericin, a silk-derived protein recovered as a by-product of the textile industry, is a renewable biomacromolecule with considerable potential for sustainable material development. Chemical modification represents an effective strategy for its valorization. In this study, acetylation using acetyl chloride (AcCl) was selected as a model reaction to systematically investigate the reactivity of sericin in an N,N-dimethylacetamide/lithium chloride (DMA/LiCl) solvent system and to evaluate the influence of reaction parameters on both the extent of functionalization and protein secondary structure. A Design of Experiments (DoE) strategy, comprising an initial full factorial screening followed by Box–Behnken optimization, was employed to investigate the effects of AcCl equivalents, sericin concentration, and LiCl content. A quantitative FTIR workflow based on constrained Gaussian deconvolution was developed to derive functionalization index (FI) and β-sheet index (BI) from both peak areas and peak intensities, enabling the simultaneous evaluation of chemical modification and structural organization. The exploratory screening identified AcCl as the dominant factor governing sericin functionalization. During the optimization phase, the FI models described the general response trends, whereas the BI was successfully represented by robust quadratic models (R² = 0.977–0.978; adjusted R² = 0.936–0.938), revealing significant linear, interaction, and quadratic effects, with LiCl concentration and sericin concentration playing key roles in governing structural organization. The analytical workflow was verified by reproducibility assessment and independent validation experiments. Overall, this study proposes a quantitative DoE–FTIR framework for systematically investigating sericin functionalization and its associated structural evolution, providing support for future studies aimed at sericin industrial valorization. Full article

Inflammation is a physiological response of the body to infection and tissue damage; dysregulated inflammatory signaling can cause the initiation and aggravation of a variety of chronic diseases. Although anti-inflammatory drugs have been commercialized and showed beneficial effects clinically, their long-term application is often limited by loss of effects and adverse side effects. Natural polysaccharides are multifunctional biomacromolecules with strong potentials in inflammation therapy due to their inherent biocompatibility, wide immunomodulation property and drug capacity. In this Review, we offer a holistic summary of recent advances in polysaccharide anti-inflammatory strategies by coupling the characteristics of structure, biological mechanism and polysaccharide-based delivery systems. This review gives a comprehensive overview of the rational design of anti-inflammatory strategies based on polysaccharides, and also points out the current limitations of polysaccharide drugs in applications, translation difficulties and future trends. Full article

Glycosaminoglycans (GAGs) are the carbohydrate portion of proteoglycans (PGS), a family of complex biomacromolecules ubiquitously found in the extracellular matrix and on cell surfaces that play critical roles in a plethora of physiological and pathological processes. In the present work, chondroitin sulfate (CS) and dermatan sulfate (DS) were extracted and purified from the head (GCB) and skin (GDB) of blue runner fish (Caranx crysos) to explore their structural features and biological properties. GCB and GDB were purified by ion-exchange chromatography with yields of 0.82% and 0.61%, respectively. Chemical and structural analysis showed that GCB and GDD demonstrated quite similar sulfation degrees (4.45% and 4.24%, respectively). The molecular weight values obtained for GCB and GDB as estimated by high-performance size exclusion chromatography coupled with a triple detector array (HP-SEC-TDA) were 48.9 and 28.54 KDa, respectively. Structural features were elucidated using FT-IR and 2D NMR spectroscopy. GCB was mainly identified as chondroitin sulfate, containing 82% GlcA and minor proportions of IdoA and IdoA2S (scoring 18% dermatan-like structures). In contrast, GDB was predominantly dermatan sulfate, with a higher unsulfated IdoA content (54%) and a lower GlcA percentage (17%). In vitro anticoagulant activity, evaluated using APTT and PT assays, demonstrated that both GAGs exhibit significant anticoagulant potential. In addition, both fractions exhibited no antiplatelet activity, suggesting that the isolated glycosaminoglycans selectively target the coagulation cascade without affecting platelet aggregation. Furthermore, hemolytic assays confirmed that neither GCB nor GDB showed any hemolytic activity at the tested concentrations. Cytotoxicity assessment in HEK293 and HUVEK cell lines further confirmed the absence of detectable toxicity even at high concentration. Overall, these marine-derived GAGs present promising therapeutic potential as a source of anticoagulant drugs. Full article

Dry eye disease (DED) is a chronic inflammatory disorder of the ocular surface, characterized by tear film homeostasis imbalance, with aging being identified as a crucial independent risk factor. Oxidative stress, which refers to the excessive production of reactive oxygen species (ROS) and reactive nitrogen substances during mitochondrial metabolism and the weakened protective effect of antioxidants, plays a central role in this process. With aging, the mitochondrial function of ocular surface tissues, such as the corneal epithelium, meibomian glands, and lacrimal glands, declines. Concurrently, the activity of endogenous antioxidant enzymes (such as superoxide dismutase and glutathione peroxidase) decreases, and the levels of tear antioxidants such as lactoferrin also decrease. These age-related changes collectively lead to excessive accumulation of ROS, triggering oxidative stress that directly damages biomacromolecules in ocular surface cells and impairs the stability of the tear film. Furthermore, we have summarized the current therapeutic strategies for oxidative stress in DED, including both conventional antioxidants and emerging approaches such as eye drops based on nanoenzymes, thermosensitive hydrogels, intense pulsed light therapy, and drug-eluting contact lenses. By combining the new progress in the delivery systems of biomaterials-based drugs with mechanism-guided interventions, this review systematically establishes the intimate functional linkages between mitochondrial dysfunction, oxidative stress, and the pathogenesis of DED and focuses on elaborating the translational potential of advanced biomaterials-based antioxidant regimens, aiming to provide novel foundations and insights theoretical for the development of more effective and precise therapeutic strategies for DED. Full article

Modification of PLA with functional nanoparticles is a promising approach for imparting new properties to the material. In this work, titanium nanoparticles (Ti NPs) and titanium dioxide nanoparticles (TiO₂ NPs) were synthesized by laser ablation and characterized by dynamic light scattering, spectrophotometry, and transmission electron microscopy. The average hydrodynamic diameter of Ti NPs was 12 nm, while that of TiO₂ NPs was 24 nm; both dispersions possessed a positive zeta potential (23–27 mV) and spherical morphology. L-PLA composite films containing 0.1 wt.% Ti NPs or TiO₂ NPs were obtained by solution casting. Atomic force and modulation-interference microscopy confirmed the uniform distribution of nanoparticles within the polymer matrix, although partial aggregation was observed. The introduction of TiO₂ NPs increased the water contact angle. Mechanical testing revealed a significant reinforcing effect: the addition of 0.1 wt.% NPs increased the Young’s modulus by 62–68% and the ultimate tensile strength by 16–18% while maintaining a ductile fracture pattern with elongation at break up to ~8%. Both types of composites generated reactive oxygen species (ROS) in aqueous solutions: Ti NPs increased H₂O₂ production by 5.5 times and TiO₂ NPs by 4.9 times, and they also induced the formation of hydroxyl radicals. The accumulation of 8-oxoguanine in DNA and long-lived oxidized protein species confirmed the materials’ ability to cause oxidative damage to biomacromolecules. For E. coli, growth inhibition reached 40.5% (for composites with Ti NPs) and 71% (for composites with TiO₂ NPs). The effect was even more pronounced for S. aureus, where inhibition levels were approximately 70% and 80%, respectively; flow cytometry confirmed the strong bactericidal effect, showing that materials containing TiO₂ NPs increased the proportion of dead cells to 25% for E. coli and ~68% for S. aureus. Cytotoxicity assessment on human fibroblasts (HSF) demonstrated the high biocompatibility of neat L-PLA and composites with Ti NPs (viability > 95%) and with TiO₂ NPs (viability ~93%). The obtained results indicate that L-PLA-based composites with Ti NPs and TiO₂ NPs exhibit pronounced ROS-mediated antibacterial activity without additional UV irradiation. These findings position these materials as highly promising candidates for active biodegradable food packaging to extend shelf-life and for biomedical devices, such as wound dressings and implants, where reducing the risk of bacterial colonization is critical. Full article

Hydrogels constructed from natural biomacromolecules with multifunctional properties, such as improved mechanical strength, ionic stability, biocompatibility, and ionic conductivity, are highly desirable for advanced food and biomedical applications, yet remain challenging to design. Although alginate is one of the most widely used hydrogel-forming polysaccharides due to its biocompatibility and gelation ability, its intrinsic limitations often hinder the development of hydrogels with fully optimized performance. This review provides a systematic comparison of alginate-based composite hydrogels formed with complementary biopolymers, including whey proteins, gelatin, pectin, starch, and chitosan, focusing on their synergistic effects on structural, mechanical, and functional properties. Recent studies are critically analyzed to elucidate how polymer–polymer interactions influence gel network formation, environmental ionic stability, and encapsulation performance. Particular attention is given to fabrication strategies and formulation parameters that enhance the immobilization and controlled release of probiotics, vitamins, polyphenols, and other bioactive compounds. By integrating current knowledge on structure–function relationships and processing approaches, this review offers practical design guidelines for the development of multifunctional alginate-based hydrogel systems for applications in functional foods and nutraceutical delivery. Full article

Among the most structurally diverse biomacromolecules, polysaccharides have attracted increased attention as nanocarriers for precision medicine due to their inherent biocompatibility and versatility in functionalization. Molecular features, such as monomer composition, glycosidic linkages, charge density, and chemical modification, essentially determine the nanoscale assembly process of these biopolymers, as well as their biological compatibility. This review highlights the role of these properties in the assembly process of polysaccharide-based nanocarriers leading to a variety of self-assembled nanostructures, such as polyelectrolyte complexes, protein–polysaccharide complexes, amphiphilic micelles, vesicles, hybrid systems, and nanogels, which are extensively discussed throughout the review. This review also focuses on the structure–property–function relationships of nanocarriers as applied to the rapidly developing area of precision medicine, emphasizing the problems of sustainability and reproducibility. By combining the principles of molecular engineering, supramolecular assembly, and measurable properties, this work aims to present a unified view of the molecular engineering of polysaccharide-based nanocarriers for enhanced translation potential, as well as to outline a coherent framework for the rational development of next-generation polysaccharide-based nanocarriers with improved clinical relevance. Full article

Marine algae, microalgae, and Cyanophyceae emerge as sustainable and versatile sources of biomacromolecules for the fabrication of hydrogels with broad biomedical potential. Their phycocolloids, such as alginate, agar, carrageenan, ulvan, and extracellular polysaccharides (EPS), exhibit intrinsic biocompatibility, tunable gelation behavior, and bioactive sulfated structures that support cell viability, tissue regeneration, and therapeutic delivery. This review provides a comprehensive overview of hydrogel fabrication strategies, including physical, chemical, and hybrid crosslinking approaches, and highlights recent advances in composite systems incorporating proteins, glycosaminoglycans, and functional nanomaterials. Applications in skin repair, cartilage and bone regeneration, neural and cardiovascular engineering, and controlled drug delivery are examined, alongside the expanding role of marine-derived hydrogels as bioinks for 3D and 4D bioprinting. Despite their promise, challenges remain related to extract variability, purification complexity, mechanical limitations, and the need for standardized characterization. Future perspectives emphasize genetic engineering of algae and cyanobacteria, development of multifunctional hybrid hydrogels, sustainable large-scale production, and pathways toward clinical translation. Together, these insights position marine-derived hydrogels as next-generation biomaterials with significant potential for regenerative medicine and therapeutic innovation. Full article

Owing to their distinctive physicochemical features, their structural analogues of benzene ring bioisosteres, and their strong affinity for biomacromolecules, pyridine derivatives function both as core structural scaffolds in pharmacologically active compounds and as versatile elements for optimizing key drug-like properties, such as water solubility, membrane permeability, and metabolic stability. In this study, we synthesized five pyridine-fused heterocyclic compounds using common synthetic intermediates as precursors. Full article

Inspired by natural scaffolds, artificial scaffolds have garnered significant attention in recent years. Compared with synthetic scaffolds such as organic and polymer scaffolds, biological scaffolds from the foundational biomolecules nucleic acids (DNA/RNA) and proteins demonstrate distinct advantages in the assembly of inorganic nanoparticles and proteins, as well as in drug delivery. These advantages stem from their exquisite spatial structures, genetically encoded programmability, and their favorable biocompatibility, which is attributed to natural building blocks and degradable backbones that minimize long-term cytotoxicity. The intrinsic properties and structural symmetry of biomacromolecules as building blocks often determine the properties of the corresponding assemblies, and thus greatly influence their functions. In this review, we classify bottom-up constructed biological scaffolds according to these two primary constituent classes (nucleic acids and proteins) to examine their framework structures and key features. We also discuss the relevant applications of artificial bioscaffolds. As an emerging class of nanomaterial with precise structures and genetic programmability, biological scaffolds hold significant promise for future development. Full article

As a traditional dual-purpose ingredient for both medicine and food, the biomacromolecules in Panax ginseng include polysaccharides, pectin, exosomes, proteins and dietary fiber. Due to their unique chemical structures, physiological activities, and processing adaptability, these components have achieved diversified applications in the medical field, becoming one of the core raw materials for functional food development. Modern research shows that the biomacromolecules found in ginseng can regulate the body’s immunity, antioxidant and anti-tumor properties, as well as antibacterial properties and the ability to enhance the body’s metabolic capacity, demonstrating significant application potential in healthcare-related fields. Recent studies have found that in addition to the root, the stems, leaves, fruits and flowers of P. ginseng also contain various effective components such as ginseng polysaccharides and pectin, which have enhanced the utilization value of ginseng plant resources. Ginseng biomacromolecules can not only replace antibiotics but also improve the production performance of animals by influencing the structure of intestinal flora, providing raw materials for the selection and application of natural feed additives for animals. This review summarizes the latest research findings on the pharmacological properties and practical applications of ginseng-derived biomolecules. It primarily addresses the structural characteristics, pharmacological activities, and current applications in health and medicine of biomolecules such as ginseng polysaccharides, ginseng exosomes, ginseng proteins, and ginseng dietary fiber. It aims to provide a fresh perspective and a solid theoretical foundation for the in-depth development of ginseng in the fields of medicine and molecular biology. Full article

ILs have emerged as versatile formulation components in DDS due to their tunable physicochemical properties and ability to modulate biomolecular and interfacial interactions. This review examines IL-enabled DDS strategies across major delivery platforms, including nanocarrier-based systems, microtechnology-assisted devices, and biomacromolecule formulations, with emphasis on formulation design principles rather than administration route. We discuss how ILs enhance API solubility, stability, permeability, and formulation flexibility through API–IL complex formation and controlled membrane interactions and relate mechanistic insights into IL–membrane interactions to both delivery performance and safety via structure–activity relationships. Current limitations, including toxicity concerns, lack of standardized evaluation criteria, scalability challenges, and regulatory ambiguity, are critically assessed. Overall, this review positions ILs as formulation-enabling materials rather than standalone therapeutics and underscores the importance of rational design, standardized assessment, and early regulatory alignment for advancing IL-enabled DDS toward clinical translation. Full article

The industrial application of free sucrose phosphorylase (SPase) is significantly limited due to cost, stability issues, and poor reusability. In this study, we employed organic–inorganic hybrid nanoflowers to achieve cell immobilization by co-assembling metal ions with cells. The surface of cells was coated with nanoflowers via chitosan-regulated biomimetic mineralization, thereby enhancing the activity of immobilized cells while providing a protective structure to improve stability. The relative activity of the immobilized cells was 30% higher than that of the free cells. After placing at 4 °C in 15 days, the relative activity of immobilized cells (80%) was substantially higher than that of free cells (40%). Moreover, the immobilized cells retained approximately 85% of their relative activity after 10 cycles. In summary, the novel biocatalysts developed in this study combine high catalytic performance with excellent reusability, demonstrating significant advantages in E. coli cell immobilization and providing a solid foundation for their application in industrial biocatalysis and related fields. Full article

Human serum albumin (HSA) is one of the main proteins in human blood plasma and serves as a molecular “taxi” transporting various compounds, including organic compounds, drugs, metal ions, etc., through the circulatory system throughout the human body. As with any other proteins, HSA hydration plays an important role in maintaining its structure and functioning as well as influencing its ability to bind to ligands. This contribution presents, for the first time, a generalized picture of hydration of this biomacromolecule obtained within the framework of the 3D-RISM (three-dimensional Reference Interaction Site Model) theory of solvation. Based on 3D isodensity maps and structural parameters (hydration numbers, hydration layer thickness, fraction of hydrogen bonds, SASA, etc.), the most probable model of HSA hydration structure was reconstructed. With the description of HSA hydration, two important issues were also addressed in detail. The first is the correct determination of the hydration layer thickness, a common problem in protein science. The second is the possible state and behavior of hydration water in HSA–ligand binding. The presented results provide a deeper understanding of the relationship between solvent and HSA, which brings new knowledge to the understanding of protein hydration. Full article